Dr. Jim Sample

Education

Specialties

Research interests

My research focuses on fluid flow in the
upper crust in active tectonic environments. I am interested in developing new
ways to investigate the record of fluid flow in fault systems in order to
understand the plumbing of fluid systems and how fluid-rock interactions affect
rock properties over short and long time periods.

The results of this research bears on the
evolution of fluid circulation in the crust, deformation mechanisms and
seismicity at active margins, redistribution of elements in the marine system,
and perhaps on the evolution of life in extreme environments. My students,
colleagues, and I investigate these processes using a variety of analytical
techniques. Each project involves a substantial component of:

field mapping

rock characterization

sample collection—using the good old
Brunton compass

high-precision mapping

tools for field measurement of rock
permeability.

We characterize the cements and fabrics
of the samples using petrography and image analysis including scanning electron
microscopy and associated imaging techniques. We try to unravel fluid flow
histories and the evolution of fluid sources by combining petrographic studies
with mass spectrometry, focusing on the trace-element, stable, and radiogenic
isotope geochemistry of precipitates left behind by fluids passing through the
system.

My current areas of research are
carbonate cements and veins preserved in active faults in the Cascadia
subduction zone, deformation bands and petroleum migration along the Newport-
Inglewood fault zone in southern California, a Paleocene cold seep deposit
(chemoherm) on the west side of the San Joaquin Valley, California, and fault
systems in coarse-grained clastic rocks of the Colorado Plateau. In addition to
basic scientific research, I am involved in projects to improve and increase
Earth science education at the K-16 level.